We present a new family of contrast agents, based on targeting the maltodextrin transporter termed maltodextrin based imaging probes (MDPs), which are designed to image infections associated with implanted medical devices by fluorescent imaging. The chemical structure of an MDP is composed of maltodextrins conjugated to the positron emitting radioelement fluorine-18. MDPs have the potential to offer significant advantages over existing methods for imaging bacteria, such as FDG, as a result of their high specificity and sensitivity for bacteria. MDPs target the maltodextrin transport pathway and are internalized as a major source of glucose by bacteria. MDPs can therefore deliver millimolar concentrations of imaging probes into bacteria, making it possible to image low numbers of bacteria. MDPs also have high specificity for bacteria because mammalian cells do not express the maltodextrin transporter and thus cannot internalize contrast agents conjugated to maltose. Finally, MDPs are composed of glucose oligomers, which are hydrophilic and membrane impermeable. MDPs are therefore efficiently cleared from un-infected tissues in vivo, leading to low background in organs such as the heart and muscle, which should lead to high sensitivity imaging of implanted device infections. These unique properties allow MDPs to accurately image small numbers of bacteria in vivo. MDPs thus have the unique properties allow MDPs to accurately image small numbers of bacteria in vivo. MDPs thus have the potential to detect implant device infections at an early stage and enable their treatment before they are challenging to eradicate.